<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 200px;
            height: 200px;
            background: greenyellow;
            line-height: 300px;
        }
        p {
            width: 200px;
            height: 200px;
            background: palevioletred;
        }
        span {
            color: aquamarine;
        }
    </style>
</head>
<body>
    <!-- 1、块级元素 -->
     <div>我是div标签，我是块级元素</div>
     <p>我是p标签，我是块级元素</p>
     <span>我是span标签，我是行级标签</span>
</body>
</html>